Nasal pillows with high volume bypass flow and method of using same

Abstract

A fan unit which in use forms part of a gases supply unit, the gases supply unit suitable for use as part of a system for providing heated humidified gases to a user, the fan unit having a casing that has an inlet aperture and an outlet passage, the outlet passage including an exit aperture, the fan unit also including a fan which is located inside the casing and which is adapted for connection to a motor to drive rotation of the fan in use, the fan drawing gases into the casing via the inlet aperture, and forcing these gases out of the casing via the outlet passage as a gases stream, the outlet passage further including at least one bypass vent hole independent of the exit aperture and arranged at an angle to the path of the gases stream through the outlet passage.

1 .- 20 . (canceled) 
     
     
         21 . A patient interface for providing gases at a pressure above atmospheric pressure to a patient, the patient interface comprising;
 a hollow main body comprising;
 an inlet configured to attach to a conduit to receive a stream of respiratory gases, 
 an outlet configured to seal with an airway of said patient to provide respiratory gases from the conduit to the patient; and 
 a vent configured to vent exhaled gases through the main body, 
   wherein the hollow main body is internally divided into two portions such that a first passage configured to deliver the respiratory gases to the patient is formed through the inlet and a first portion of the hollow main body and a second passage configured to vent the exhaled gases from within the hollow main body to atmosphere is formed through a second portion of the hollow main body and the vent, and   wherein the first and second passages are separated from each other so that, in use, the intermingling of the respiratory and exhaled gases is avoided as the respiratory or exhaled gases travel through the first or second passage, respectively.   
     
     
         22 . The patient interface defined in  claim 21 , wherein the patient interface further comprises a seal which includes the outlet. 
     
     
         23 . The patient interface defined in  claim 22 , wherein the seal is configured to form a seal with nares of the patient. 
     
     
         24 . The patient interface defined in  claim 21 , wherein an inlet to the second passage is located to be immediately adjacent nares of the patient when the patient interface is fitted to the patient. 
     
     
         25 . A patient interface for providing gases at a pressure above atmospheric pressure to a patient, the patient interface comprising:
 a housing including an inlet configured to attach to a conduit to receive a stream of gases; and   a seal including an outlet that is fluidly connected to the housing for delivery of the stream of gases to the user, the seal being configured to seal against nares of the patient,   wherein the seal is divided into first and second passages which are sealed from each other so that there is no intermingling of the gases with other gases when the gases or the other gases are in the first or second passage, respectively, and   wherein the first passage is configured to enable the gases to be delivered to the patient and the second passage is configured to allow a majority of the other gases to vent to atmosphere as the patient exhales.   
     
     
         26 . The patient interface defined in  claim 25 , wherein the second passage is configured to vent the other gases to the atmosphere through the housing. 
     
     
         27 . The patient interface defined in  claim 25 , wherein the second passage is configured to vent the other gases to the atmosphere through a vent at the seal. 
     
     
         28 . The patient interface defined in  claim 25 , wherein the housing comprises a hollow main body. 
     
     
         29 . The patient interface defined in  claim 25 , wherein the seal is part of an interface portion configured to interface with the patient's airway. 
     
     
         30 . A patient interface for providing gases at a pressure above atmospheric pressure to a patient, the patient interface comprising:
 a hollow main body including:
 an inlet configured to attach to a conduit to receive a stream of gases; and 
 an outlet configured to seal against nares of the patient to deliver the stream of gases to the patient; and 
   first and second passages which are sealed from each other so that intermingling of the gases with other gases as the gases or the other gases travel through the first or second passage, respectively, is avoided,   wherein the first passage is configured to enable the gases to be delivered to the patient and the second passage is configured to allow a majority of the other gases to vent to atmosphere as the patient exhales.   
     
     
         31 . The patient interface defined in  claim 30 , wherein the patient interface further comprises an interface portion that is fluidly connected to the hollow main body and wherein the interface portion includes the outlet. 
     
     
         32 . The patient interface defined in  claim 31 , wherein the interface portion includes the first and second passages. 
     
     
         33 . The patient interface defined in  claim 30 , wherein the second passage is configured to allow the majority of the other gases to vent immediately to the atmosphere. 
     
     
         34 . The patient interface defined in  claim 31 , wherein the second passage is configured to vent the other gases to the atmosphere through the interface portion. 
     
     
         35 . The patient interface defined in  claim 30 , wherein the second passage is configured to vent the other gases to the atmosphere through the hollow main body. 
     
     
         36 . The patient interface of  claim 30 , wherein the outlet is constructed of soft rubber or silicone. 
     
     
         37 . The patient interface of  claim 30 , wherein the hollow main body comprises a pressure measurement duct. 
     
     
         38 . The patient interface of  claim 31 , further comprising a pressure sensor located on or in the interface portion. 
     
     
         39 . The patient interface of  claim 30 , wherein the outlet is configured to form a seal with respect to the patient's nares and mouth. 
     
     
         40 . The patient interface of  claim 30 , further comprising a headgear assembly configured to hold the interface portion in position on the patient's head. 
     
     
         41 . The patient interface of  claim 30 , comprising a vent that is in fluid communication with the second passage and is configured to vent 50 to 70 Litres per minute of the other gases at a pressure of 10 cmH 2 0.